A growing interest has developed for the direct optical control of semiconductor devices due to the potential applications in phased array radar and communications. The following list of documents comprises a sample of articles which concern the design and optical control of such devices.
1. A. S. Daryoush, "Optical Synchronization of Millimeter-Wave Oscillators for Distributed Architectures," IEEE Trans. Microwave Theory Tech., Vol. 38, pp. 467-476, May 1990; and a related article by, K. Kurokawa, "Injection Locking of Microwave Solid-State Oscillators," Proc, IEEE 61, 1386 (1973).
2. A. J. Seeds and A. A. A. DeSalle, "Optical Control of Microwave Semiconductor Devices," IEEE Trans. Microwave Theory Tech., Vol. 38, pp. 577-584, May 1990.
3. T. C. L. G. Sollner, E. R. Brown and H. Q. Le, "Microwave and Millimeter-Wave Resonant-Tunneling Devices," Lincoln Lab. Jour., Vol. 1, pp. 89-105, 1988.
4. S. C. Kan, S. Sanders, G. Griffel, G. H. Lang, S. Wu, and A. Yariv, "Optical Switching of a New Middle Trace in an Optically Controlled Parallel Resonant Tunneling Device-Observation and Modeling," Appl. Phys. Lett., Vol. 58, pp. 1548-1550, 1991.
5. P. England, J. Yee, L. T. Florez, J. P. Harbison and J. E. Golub, "Optical Switching in Resonant Tunneling Structures," Conference on Quantum Electronics Laser Science, May 12-17, 1991, Baltimore, Md., 1991 Technical Digest Series, Vol 11, p. 34, 1991.
6. D. J. Struzbecher, J. F. Harvey, T. P. Higgins, A. C. Paolella, and R. A. Lux, "Direct Optical Frequency Modulation of a Resonant Tunnel Diode Oscillator," submitted to IEEE Electron Device Lett., Jul. 29, 1991.
7. L. L. Chang, L. Esaki and R. Tsu, "Resonant Tunneling in Semiconductor Double Barriers," Appl. Phys. Lett., Vol. 24, pp. 593-595, 1974.
8. I. Mehdi, R. K. Mains, and G. I. Haddad, "Effect of Spacer Layer Thickness on the Static Characteristics of Resonant Tunneling Diodes," Appl. Phys. Lett. 57, 899 (1990); and a related article by J. E. Oh, I. Mehdi, J. Pamulapati, P. K. Bhattacharya, and G. I. Haddad, "The Effect of Molecular Beam Epitaxial Growth Conditions on the Electrical Characteristics of In.sub.0.52 Al.sub.0.48 As/In.sub.0.53 Ga.sub.0.47 As Resonant Tunneling Diodes," J. Appl. Phys. 65, 842 (1989); I. Mehdi, R. K. Mains, G. I. Haddad, and U. K. Reddy, "Properties and Device Applications of Deep Quantum Well Resonant Tunneling Structures," Surf. Sci. 228, 426 (1990); and also by the same authors, R. K. Mains, I. Mehdi, and G. I. Haddad, "Effect of Spatially Variable Effective Mass on Static and Dynamic Properties of Resonant Tunneling Devices," Appl. Phys. Lett. 55, 2631 (1989).
9. C. J. Arsenault and M. Meunier, "Proposed New Resonant Tunneling Structures with Impurity Planes of Deep Levels in Barriers," J. Appl. Phys. 66, 4305 (1989).
10. R. L. Wang, Y. K. Su, Y. H. Wang, and K. F. Yarn, "Negative Differential Resistance of a Delta-Doping-Induced Double Barrier Quantum-Well Diode at Room Temperature," IEEE Electron Dev. Lett. 11, 428 (1990).
11. V. K. Reddy, A. J. Tsao, S. Javalagi, G. K. Kumar, D. R. Miller, and D. P. Neikirk, "Quantum well injection transit time (QWITT) diode oscillators," in Conference Digest Fifteenth International Conference on Infrared and Millimeter Waves, 10-14 December 1990, Orlando, Fla., ed. R. J. Temkin, (SPIE vol. 1514), p. 88.
12. J. M. Gering, T. J. Rudnick, and P. D. Coleman, "Microwave Detection Using the Resonant Tunneling Diode," IEEE Trans. Microwave Thry. and Tech. 36, 1145 (1988).
13. T. C. L. G. Sollner, P. E. Tannenwald, D. D. Peck, and W. D. Goodhue, "Quantum Well Oscillators," Appl. Phys. Lett. 45, 1319 (1984); and a related article by, E. R. Brown, T. C. L. G. Sollner, W. D. Goodhue, and C. D. Parker, "Millimeter-Band Oscillations Based on Resonant Tunneling in a Double-Barrier Diode at Room Temperature," Appl. Phys. Lett. 50, 83 (1987).
14. G. Keiser, Optical Fiber Communications, (McGraw-Hill, N.Y., 1983) and see C. K. Kao, Optical Fiber Systems: Technology, Design, and Applications, (McGraw, 1982).
As is evident from the above cited references, the technology of building resonant tunnel diodes (RTDs) is well established. As well, the technology of microwave light generation and delivery using lasers, light emitting diodes, plasma tubes and the like in combination with intensity modulators and fiber optics is also well known. Therefore, as is suggested by the above identified references, one skilled in the art would readily be able to design any number of optical or integrated optic systems to deliver intensity modulated light in the microwave power range with photon energies above the bandgap of a semiconductive device material to the semiconductive device and incorporate such a semiconductive device in oscillator circuit applications.
An example of an important technical field where such semiconductor devices would be able to be directly incorporated is in phased array radar and communication systems. As suggested by reference 1, these semiconductor devices would synchronize active oscillator modules distributed over an antenna array. One means of achieving synchronization, as suggested by reference 1, is by injection locking oscillators with a direct optical signal delivered over optical fibers. In relation to reference 1, reference 2 describes the various means which are available to optically control semiconductor devices, including the direct optical injection locking of oscillators utilizing IMPATTS, FETs, and HEMTs. However, these semiconductor devices lack some of the enhanced performance characteristics of RTDs and, therefore, synchronization of oscillator modules would be further optimized by optically controlling RTDs incorporated in such oscillators.
The present invention addresses this present need for direct optical control of an RTD to injection lock an RTD oscillator.